import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner scanner = new Scanner(System.in);

		System.out.print("上次成绩:");
		double previous_success = scanner.nextDouble();

		System.out.print("本次成绩:");
		double this_success = scanner.nextDouble();

		double increase_percent = (this_success - previous_success) / previous_success * 100;
		System.out.printf("提高了:%.2f%%\n"increase_percent);
	}
}